Evaluating the Efficacy of the Diluted Schirmer Method for Tear Collection in Dry Eye Syndrome Patients.

Purpose: This study assesses the diluted Schirmer method's effectiveness in collecting tears from dry eye syndrome patients, aiming to identify the most suitable tear collection technique for them.
Methods: A prospective study. Tear samples were collected from patients with dry eye syndrome and healthy individuals using two methods: (1) Direct Schirmer Method: Schirmer strips were directly inserted into the eye to collect tears. (2) Diluted Schirmer Method: After instilling physiological saline into the eye and waiting for 30 s to ensure thorough mixing with tears, Schirmer strips were used for collection. Tear samples from both groups were analyzed and compared for total protein and cytokine levels (IL-1β, IL-6, IL-8, TNF-α).
Results: (1) The study included 32 participants: 16 with dry eye syndrome (4 males, 12 females, average age 34.92 ± 10.13 years) and 16 healthy controls (5 males, 11 females, average age 32.25 ± 9.87 years). (2) The diluted Schirmer method produced a significantly larger tear volume compared to the direct method ( p  < 0.05), with lower Visual Analogue Scale (VAS) scores indicating less discomfort ( p  < 0.05). (3) The average total protein content of the two groups was 51.70 ± 3.166 ng measured by Direct Schirmer method, and the average total protein content of the Diluted Schirmer method was 50.05 ± 3.263 ng. There was no statistical difference between the two groups. ( t  = 1.051, p  = 0.3098) (4) The concentrations of total tear protein and various cytokines measured by both methods were higher in the dry eye group compared to the normal group, with statistically significant differences ( p  < 0.05). Both methods reflected consistent changes in tear protein profiles.
Conclusion: The diluted Schirmer method can comfortably collect an adequate volume of tear samples in a short time and consistently reflect changes in tear proteins, making it an effective method for tear collection in patients with dry eye syndrome.